Method of making phonograph record blanks from composite material



Jan. 8, 1963 s. SALZMAN 3,072,519

METHOD OF MAKING PHQNOGRAPH RECORD BLANKS FROM COMPOSITE MATERIAL Filed Aug. 29, 1958 FIG. 1.

1' SHMAEZ 50 2,444 i v JNVENTOR.

United States Patent Qfiice 3,072,519 METHOD OF MAKING PHONOGRAPI-I RECORD BLANKS FROM COMPOSITE MATERIAL Samuel Salzrnan, North Hollywood, Calif., assiguor to Allied Record Manufacturing Co., Los Angeles, Calif., a corporation oi. California Filed Aug. 29, 1958, Ser. No. 758,006 1 Claim. (Cl. 156-200) This invention relates to a method and apparatus for making phonograph records and more particularly to such a method and apparatus for continuously coating paper with a controlled thickness of a special resin, stamping into the resinous surface the sound grooves in two side-by-side positions on the roll, folding the resin coated and stamped paper about a central core and then die cutting the resulting blank records from the roll.

It is accordingly one object of this invention to provide such a continuous process of making record blanks.

It is another object of this invention to provide a method and apparatus for manufacturing phonograph records which is simple, economical and easy to control.

These and other objects, features and advantages will be apparent from the annexed specification, in which:

FIGURE 1 is a side view partly in section of a device embodying the present invention.

FIGURE 2 is a perspective elevation of the stamping roll and dies.

FIGURE 3 is a section taken along the line 33 of FIGURE 1.

Referring now more particularly to the drawings and particularly to FIGURE 1, there is provided a roll 28 of suitable paper from which the paper is unrolled and passed over a support 11 adjacent which it receives a coating 12 of a special resin from the resin applicator 13, the thickness of which coating is controlled by an adjustable doctor blade 14. The resin is applied hot and in liquid form, but the distance between the doctor blade 14 and the stamping roll 15 in practice is adjusted to be sufficient so that the resin coating 12 has cooled and solidified prior to reaching the stamping roll 15. Stamping roll 15 cooperates with a roll 16 which is provided with a cover 17 of a resilient material such as rubber or the like and which is itself adjustable in height by means of adjusting screws 27 (only one shown) associated with each end of the supporting shaft of roll 16. Roll 16 may be raised or lowered by adjusting screws 27 so as to provide the proper pressure between the rolls 15 and 16. The roll 15 is heated as by heating coil 18 and is provided with a plurality of dies 19.

It will be noted that the dies 19 are placed upon the roll 15 in two series of side-by-side pairs so that as the resin coated paper passes through the rolls 15 and 16, side-by-side impressions 20 and 21 having the sound recording grooves stamped therein by the dies 19 are formed upon the resin coated paper.

A roll 29 of a flat core material 22 of any suitable type, preferably coated with a pressure sensitive adhesive, is positioned as indicated, and as the paper having the resinous coating and the die impressed recording grooves passes the roll 29, it is folded as at 23 so that each pair of die impressions 20 and 21 is placed back to back about the core material 22. The core material 22 may be of any thickness, rigidity, composition or material 3,072,519 Patented Jan. 8 1963 which will provide the structural strength desired in the final product.

Further in the path of the travel in the thus folded assembly, there is provided a die stage including a cutoif die 24 and a punch 25 which punches out the individual records 26 which, as indicated in FIGURE 3, will contain a core, two thicknesses of paper and a pair of die impressed recording grooves 20 and 21.

The success of the above-described method and apparatus is dependent upon the use of a suitable resin, which among other characteristics must be tough and wear resistant, shock proof and water proof. It must be very adhesive to paper when cool and have a rather sharp and'uniform softening point. It must also be capable of reproducing recorded sound well and be free from needle noises. Eastman Chemical Product Companys hot-melt butyrate material designated as MP- 7l-2 and as EAB is a recommended resin. This resin as ofiered to the trade is a compound comprising half-second butyrate as a film former 55% by weight, polyvinyl acetate for adhesion and gloss 5%, a product known as Paraplex G-SO as a plasticizer 25% by weight, a product known as Dow 276V9 for adhesion 14.89% by weight, 0.1% by weight of a suitable stablizer, and as the foregoing has the odor of rancid butter, 0.01% of a suitable masking agent to mask the odor is generally added. The half-second butyrate film former has the characteristic composition:

The polyvinyl acetate has the characteristic composition:

The Paraplex G-50 has the characteristic composition:

The Dow 27 6-V9 adhesion agent has the characteristic composition:

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While there has been described what is at present considered the preferred embodiment of the invention, it will be understood that various changes and alterations may be made therein without departing from the essence of the invention and it is intended to cover herein all such changes and alterations as come within the true scope and spirit of the annexed claim.

I claim: tinuously stamping from the folded strip blanks having A process of making phonograph record blanks comrecording impressions on both sides of a core material. prising the steps of continuously feeding a strip of paper; continuously applying a thin coat of resin to one side References Cited in the file of this Patent of said paper; continuously impressing side-by-side pairs of circles of recording grooves on said side of said paper; 5 UNITED STATES PATENTS continuously folding said paper; continuously feeding 21 1,777,231 Shepherd Sept. 30, 1930 strip of core material between the folds of said paper; 1,937,680 Billings Dec. 5, 1933 said folds being arranged so that each member of each 2,360,973 Pcdersen Oct. 24, 1944 pair of circles of grooves is in back to back relation 10 2,528,611 Saffady Nov. 7, 1950 to the other member about said core material; and con- 2,529,083 Keefe Nov. 7, 1950 

